Lisa O'Brien, age 11, of Erie, Pa., for her question:

WHAT IS GLUTEN?

Gluten is a mixture of proteins in wheat and some other cereal grains that helps to make dough rise. Gluten is a tough, sticky, somewhat elastic substance. It has almost no taste and is grayish yellow in color.

Gluten in wheat flour is composed chiefly of two proteins: gliadin and glutenin. It can be separated from the flour if a dough is made from flour and water and then kneaded gently under running cold water. The starch washes away until only gluten remains.

In breadmaking, the gluten in the dough traps the carbon dioxide produced by yeast. As the gas expands, it stretches the gluten, causing the dough to rise.

The amount of gluten in flour depends on the kind of wheat used. Gluten usually makes up about 88 percent of the protein in bread.